Shift+Plus or Numpad Plus to like, Shift+Minus or Numpad Minus to dislike. Can't get any simpler.
Basically, copies the like/dislike shortcut from YouTube Music, which means:
• Shift+Plus (on the number row) to like a video
• Shift+Minus (on the number row) to dislike
• Numpad Plus to like
• Numpad Minus to dislike
Additionally:
• Pressing the like/dislike shortcut will only rate the video once, i.e., pressing again won't un-rate it
• To un-rate, use Shift+0 (on the number row)
• Auto-like videos based on a watch time threshold OR based on whether you're subscribed to the current channel
• You can customize the shortcuts and the auto-like threshold
** The extension does not reveal the videos' dislike counters **
Source code: https://github.com/avi12/youtube-like-dislike-shortcut
